Enforce Case Lifecycle

We are designing our Issue Tracking implementation currently.

To ensure that the intended lifecycle is kept we wanted to use a set of variouos custom actions to promote the cases state. For exmpale "Set state to -Done-" or "Set state to -Rejected-". These custom actions should only be available under the defined circumstances. E.G. "Set state to -done" is only available, when a documentation field is filled and only for users having a certain role assigned.

We are struggling with the fact, that the "state" field is not defined as ReadOnly which cannot be changed for it is a standard field. This renders all approaches that came into our mind useless.

I guess that what we are trying to do is nothing very special and is already solved for many installations.

Ideas we had are

• using custom actions PLUS validation rules, that ensure that changes are only done in the right situation. This basically means all validation has to be entered twice. Once for the availability of the custom action and once more as a validation rule to prevent that user do the change without the custom action.
• Defining a custom field for CaseState that basically duplicates the already existing field but being defined as read only.

Both approaches are not really attractive.

How have others solved this? - Thank you for feedback and ideas!